Can You Apply Cement Screed Over Tiled Floors?
For the homeowner looking for a way to cover up ugly floor tiles applying a cement screed might offer the perfect solution, but is it okay to apply a screed over an already tiled floor?
17/12/2023
A query that pops up in my feed quite often concerns applying a cement screed over an already tiled floor. Many homeowners are looking for a way to disguise ugly tiles without going to the extreme of ripping out and replacing tiles and the application of a screed over the top of the tiles offers an easy - and reasonably inexpensive solution. But is it okay to pour a cement screed over existing tiles and what do you need to know beforehand?
Can you pour cement screed over existing tiled floor?
While you can apply a cement screed over an existing tiled floor it is not recommended. However, if the tiled floor is in excellent condition - there are no cracks in the tiles, loose grouting, stable foundation, and you are willing to take the chance then by all means go ahead. Follow the steps below for pouring a screed for a perfect level sub-floor for your choice of flooring material.
How to apply cement screed
A screed is applied over an existing concrete floor when there is a need to level the floor prior to the application of vinyl flooring, ceramic, porcelain or natural stone tiles, or laminate flooring. The thickness of a screed can vary by as much as 5mm to provide a level of flatness required for subsequent finishing. A cement screed can also be used when installing underfloor heating prior to the installation of other flooring system.
Weber's self-levelling screed is a simple process that both professional contractors and DIY enthusiasts can do. By following the steps below, you can ensure a smooth and even application of the screed, providing a durable and long-lasting surface for your project.
Step 1 - Preparation prior to application
Preparation is essential prior to the application of any floor screed and including the Weberfloor screed system. The prepared surface must have an average “surface tensile adhesion strength” greater than 1N/mm². Moreover, it should have CSP (concrete surface profile) of 3 to 4. New concrete surfaces should be at least cured for 28 days old and structurally stable (residual moisture). Use a soft brush, dry mop or vacuum cleaner to remove all traces of debris and dust. Any repairs should be done well in advance.
Step 2 - Applying the Primer
After repairs and cleaning the floor is primer with Weberfloor Primer. This latex-based primer and keying agent improves adhesion of the cement screen to the existing concrete floor. Weberfloor Primer must be applied evenly in one or two coats depending on the surface condition and porosity. Do not dilute the primer. Recommended application is two coats, using a mohair roller or brush at 2.5 – 5 m2 per litre avoiding puddling or pooling.
Step 3 - Mixing the Screed
Mix the Weberfloor 270 self-levelling screed adding the screed and water to a mixing container and mixing thoroughly until it reaches a smooth consistency. A paddle mixing attachment on the end of your drill will make this task much easier. Start at a slow speed (below 500 rpm) by slowly adding the screed to 4.6 liters of clean cool potable water. Mix for a minimum of 2 minutes until a homogeneous, lumps free mix is obtained. Scrape the sides of the mixing container and remix for 1 minute.
GOOD TO KNOW
Once mixed, the screed has to be poured within 5 to 10 minutes.
Step 4 - Pouring the Screed
Starting at a pre-designated area, pour the screed onto the prepared surface. You need to immediately start spreading it out with a notched rake suitable for the required thickness. Gently push and pull the product to aid in levelling and smoothing. It is not necessary to over rake as the product has excellent flow and workability. Ensure to work from one side of an area and spread by stepping backwards to the other side. Do not walk on the wet material unless you are wearing spiked shoes or boots.
Step 5 - Finishing
The final step requires the use of a spiked roller to roll over the wet product slowly but thoroughly to remove air bubbles and improve levelling before the setting process advances too much. Wear spiked shoes for this process.
Step 6 - The curing period
Curing occurs within 24 hours, in a controlled environment with no wind currents, at ambient temperatures within a temperature range of between 10 °C – 25 °C. Depending on layer thickness and drying conditions, after 24 hours your chosen floor covering can be installed.
Watch the video below for further information on the above process.